Tweak the list of variables for CLM_ACCELERATED_SPINUP mode

[ekluzek]

The list of variables we have when accelerated spinup mode is turned on is:

'TOTECOSYSC','TOTECOSYSN','TOTSOMC','TOTSOMN','TOTVEGC','TOTVEGN','TLAI','GPP','CPOOL','NPP','TWS'

Which should add H2OSNO to the list

This is important to be able to run the spinup stability script.

[wwieder]

Yep, thanks for adding this. Good idea and an easy update

[slevis-lmwg]

Close issue when alpha-ctsm5.4.CMIP7 merges to master.